The present disclosure relates to a multilayer ceramic capacitor and a board with the same mounted thereon.
Multilayer ceramic capacitors, multilayer chip electronic components, are chip-type condensers mounted on printed circuit boards of various electronic products such as display devices, for example, liquid crystal displays (LCDs), plasma display panels (PDPs), or the like, computers, smart phones, mobile phones, and the like, to be charged with or discharge electricity.
Since such a multilayer ceramic capacitor (MLCC) has advantages such as a small size, high capacitance, easiness of mounting, or the like, the multilayer ceramic capacitor may be used as a component of various electronic devices.
The multilayer ceramic capacitor may have a structure composed of a plurality of dielectric layers and internal electrodes alternately stacked between the dielectric layers and having different polarities.
Particularly, in a power supply device for a central processing unit (CPU) of a computer, or the like, voltage noise due to a rapid change in load current may be generated during a process of supplying low voltage.
Therefore, the multilayer capacitor has been widely used in the power supply device as a capacitor for decoupling in order to suppress voltage noise.
The multilayer ceramic capacitor for decoupling should have low equivalent series inductance (ESL) as an operation frequency is increased. Various researches into technology for decreasing ESL have been actively conducted.
Further, in order to more stably supply power, the multilayer ceramic capacitor for decoupling should have controllable equivalent series resistance (ESR) characteristics.
In the case in which ESR of the multilayer ceramic capacitor is lower than the required level, an impedance peak at a parallel resonance frequency generated due to ESL of a capacitor and plane capacitance of a micro processor package may increase, and impedance at a series resonance frequency of a capacitor may excessively decrease.
Therefore, in order to implement flat impedance characteristics in a power distribution network, the ESR characteristics of the multilayer ceramic capacitor for decoupling are required to be easily controlled.
Meanwhile, in accordance with the trend toward multifunction and a complex structure of CPU, power consumption has increased, and a rapid and large transient current may be generated in power. Therefore, importance of power integrity (PI) has increased.
The PI is to satisfy basic performance of a CPU by designing power impedance to be further decreased to suppress a change in a voltage generated according to a transient current.
Generally, a multilayer ceramic capacitor has been used as a capacitor for decoupling in order to decrease power impedance. In this case, since the transient current generated in power is a wide band current, power impedance should also be decreased in a wide band.
In addition, in accordance with the recent trend toward rapid development of mobile terminals such as tablet personal computers (PCs), ultra books, or the like, microprocessors have also been converted into miniaturized and highly integrated products.
Therefore, an area of the printed circuit board has decreased, and amounting space of the capacitor for decoupling has also been limited. Multilayer ceramic capacitors capable of being appropriately used, satisfying such a limited mounting space, have been demanded thereby.